1. Field of the Invention
The present invention relates generally to an apparatus for air conditioning. Particularly, the present invention relates to a personal air conditioner. More particularly, the present invention relates to an air conditioner system for flexible material-based devices. Even more particularly, the present invention relates to a wearable air conditioner capable of providing cool and warm air to an individual.
2. Description of the Prior Art
It has long been understood that an individual""s efficiency is related to the temperature of the individual""s body. In hot climates, creating a cooler environment for an individual increases the stamina of that individual because the body does not need to use its internal energy resources to cool the individual. In cold climates, creating a warmer environment for an individual also increases an individual""s productivity because the energy generally required by the body to produce heat is available for other uses.
Many different devices have been developed to create the preferred environmental conditions for humans. Earlier developed devices include mechanical heating, air conditioning and specialized clothing. Mechanical heating and air conditioning suffer from several drawbacks. For instance, the devices are generally bulky and stationary devices for heating/cooling a room space. They are not designed to satisfy all individual tastes of persons in the room. The specialized clothing includes garments with circulating cooling liquid.
More recent devices have included the use of thermoelectric elements as the heating/cooling engine. These include uses for environmental suits to condition and filter the air being supplied to the person within the environmental suit. There has even been developed a portable air conditioner that uses thermoelectric modules to provide cooling air to a user. Some of these more recent devices are disclosed.
U.S. Pat. No. 3,085,405 (1963, Franti) discloses a thermoelectric air conditioning apparatus for a protective garment. The garment uses a thermoelectric heat-pumping device that is attached to the back of a protective garment for conditioning and circulating air through the interior of the garment to maintain the wearer in a comfortable range regardless of wide variations in temperature of the ambient atmosphere. The portable device includes a thermoelectric heat pumping panel of generally planar form disposed within a housing structure that joins and defines airflow passages of annular shape. The walls of the housing structure are provided with apertures providing air inlets for the passageways. A first and second blower wheel are centrally disposed in the firs and second passageways and are jointly driven by a suitably mounted motor having a drive shaft extending perpendicularly through the thermoelectric panel. There is an outlet for the first airflow passageway in direct communication with the atmosphere and an outlet for the second passageway in communication with a suitable annular manifold attached to a protective garment.
U.S. Pat. No. 4,470,263 (1984, Lehovec) discloses a Peltier cooled garment. Peltier cells are attached to a garment with the cold plate of the Peltier cell in intimate thermal contact with the skin of the wearer of the garment. Heat generated by the Peltier cell is dissipated to the ambient cooling fins. Heat pipes are used to conduct the heat to the fins, or to distribute the cooling across the skin.
U.S. Pat. No. 5,193,347 (1993, Apisdorf) which was later reissued as U.S. Pat. No. Re. 36,242 (1999, Apisdorf) discloses a helmet mounted air system for personal comfort. The system includes a single lightweight thermoelectric module, mounted in a housing in turn mounted centrally atop a helmet to be worn by a worker in a hot atmosphere. The heat abstraction side of the thermoelectric module is disposed within the housing, the heat dissipation side dissipates heat to the ambient atmosphere. There is a miniature fan means to blow air through the housing and only across the user""s face. Two thermistors sense the temperature of air upstream and downstream, respectively, of the heat abstraction side of the thermoelectric module. There is a manual selection means to allow the user to set the temperature difference of air to be delivered to the face.
U.S. Pat. No. 5,197,294 (1993, Galvan) discloses a miniaturized thermoelectric apparatus for air conditioning a protective body suit. The apparatus comprises an assembly made up of a Peltier effect thermoelectric device, in the form of bimetallic or plurimetallic plates connected to a low voltage D.C. power supply. The opposed cold and hot surface of the thermoelectric device are in contact with respective heat exchangers. The assembly is contained in a housing in which two distinct and separate conduits are provided for the forced flow of air through the respective conduits of the heat exchangers.
U.S. Pat. No. 5,800,490 (1998, Patz) discloses a lightweight portable cooling or heating device with multiple applications. The modular device with an injury pack holder provides cooling and/or heating therapy to an injury, having a generally tubular shape and open first end and an open second end. A plurality of module openings are cut through the injury pack holder and covered with a retention mesh. A thermoelectric assembly containing a Peltier device, fan, radiator, first plate and second plate is installed in one of the module openings. The thermoelectric assembly transfers heat energy to a gel pack which cools or heats an area. A battery pack can be installed in another module opening or can be remotely located for operation of the thermoelectric assembly. The injury pack holder has a plurality of attachment straps for affixing the injury pack to various human and animal body parts.
U.S. Pat. No. 6,393,842 (2002, Kim) discloses an air conditioner for individual cooling/heating. The air conditioner includes a front compartment and a rear compartment separated by a partition plate made of an insulating material for forced inlet and outlet of external air therethrough, respectively. The air conditioner also includes at least two heat exchanger parts each in the upper and lower parts of front and rear compartments for making heat exchange with external air passing through the front compartment and the rear compartment, respectively. There are first drawing means and second drawing means mounted in an upper portion or a lower portion of the front compartment or the rear compartment respectively for forced circulation of the external air through the respective compartments, and driving means for driving the first and second drawing means. Each of the heat exchanger parts includes thermoelectric modules connected to a power source for absorbing heat at a heat absorptive part and discharging the heat from a dissipative part provided opposite to the heat absorptive part and heat exchangers in contact either with the heat absorptive part or the heat dissipative part of the thermoelectric module for causing heat exchange between the air flowing into the front or rear compartment and the thermoelectric module, thereby providing individual cooling/heating to a user, and constant temperature dehumidification.
Each of the devices of the prior art have various disadvantages. One disadvantage is they are limited to specialized applications such as a commercial setting requiring a protective body suit that would not be useful to other commercial or recreational applications in which a protective body suit is not wanted or needed. Another disadvantage is that the protective body suit restricts the movement of the user. A further disadvantage of some of the other prior art is that it only provides heating/cooling to certain areas of the body such as the head or neck. Yet, another disadvantage of certain prior art is that while portable it is not wearable.
Therefore, what is needed is a wearable air conditioner using thermoelectric technology that is able to provide cool and warm air to an individual wherever the individual goes. What is further needed is a wearable air conditioner using thermoelectric technology that can provide heating/cooling to a larger area of the body without the use of a full protective body suit. What is still further needed is a wearable air conditioner using thermoelectric technology that is incorporated into bulletproof apparel/body armor.
It is an object of the present invention to provide a wearable air conditioner using thermoelectric technology that is not used with a protective body suit. It is another object of the present invention to provide a wearable air conditioner using thermoelectric technology that minimizes any restriction to the movement of the user. It is yet another object of the present invention to provide a wearable air conditioner using thermoelectric technology that can provide heating/cooling to a large area of the body by being incorporated into standard apparel such as shirts, pants, jackets, dresses, skirts, footwear, headwear, gloves, shorts, under garments, etc. It is a further object of the present invention to provide a wearable air conditioner using thermoelectric technology that can be incorporated into bulletproof apparel/body armor.
The present invention achieves these and other objectives by providing one embodiment of a wearable air conditioner that includes at least one thermoelectric module, at least one fan blower to generate air flow, at least one heat sink to facilitate heat exchange, ducts and vents to distribute air, a portable power source such as batteries, solar power, fuel cells, or other outside power source to power the thermoelectric module and the fan blower, and a housing system to integrate the above components with apparel. A second embodiment is contemplated where a self-contained housing is used to allow the system to be easily carried.
Thermoelectric modules, which are solid state devices that generally include two dissimilar materials such as N-type and P-type thermoelectric semiconductor elements, work on the Peltier effect. The semiconductor elements are connected to each other through a serial electrical connection. When electric power passes through the thermoelectric module""s electrical connections between the two dissimilar semiconductors, the current induces heating or cooling at the junctions. Thus, heat will be transferred from one side of the thermoelectric module to the other side, generating a cold surface with a temperature Tc, and a hot surface with a temperature Th. In the present invention, heat sinks are attached to both the cold side and the hot side. The fan blower or blowers are used to generate two separate air streams, one passing through the cold side heat sink and becoming cooler than the ambient temperature, and the other air stream passing through the hot side heat sink and becoming hotter than the ambient temperature.
In the cooling mode, the cold air stream is used to cool the user, and the hot air is dumped into the environment. In the warming mode, the hot air stream is used to provide warmth to the user and the cold air stream is dumped into the environment.
The wearable air conditioner can be incorporated into specially designed clothing such as a jacket, footwear, headwear, gloves, etc., that can be worn by the user, providing cooling or heating wherever the user goes. The air conditioner can also be adapted to be carried by the user in various ways such as, for example, with shoulder straps where the cool or hot air can be distributed to the user""s body with hoses, ducts, vents, vented attachments, etc., and simultaneously be used to cool or heat food, beverages or other people. In addition, the air conditioner system of the present invention may also be incorporated into a sleeping bag to provide a source of heat to the occupant. This is very beneficial after sleeping for several hours during which time the body""s circulation slows down. The slow down in blood circulation produces less heat output by the body. Because conventional sleeping bags work on the principal of retaining body heat within the sleeping bag to keep the occupant warm, the decrease in body heat generation causes come users to feel cold or at least uncomfortable in that they are not as warm as they would like to be. The present invention may be incorporated to provide a separate source for heating the inside of the sleeping bag, thus keeping the user warm throughout the night.
Alternatively, the air conditioner system may also provide cooling when it is too warm for a comfortable night""s sleep. The sleeping bag will also insulate the user from the warmer outside temperature. A temperature control sensor may also be incorporated to prevent overheating or cooling during use. In fact, any device made of flexible material such as, for example, tents and similar enclosures may benefit from the incorporation of the present invention""s air conditioner system.
The system is preferably powered by high energy density, rechargeable batteries similar to those used in notebook computers or fuel cells. Several batteries may be placed into the pockets of a specially designed jacket, allowing extended usage and easy replacement. The system can also be powered by an alternative power source such as a 12V vehicle power plug whenever such a source is available. The batteries may be rechargeable by AC or DC means and by solar power, all as is well known by those skilled in the art.
The present invention provides many advantages not provided by the prior art. The wearable air conditioner is useful to individuals who have to work in a hot or cold environment. For example, soldiers in the hot desert who have to wear combat uniforms, motorcyclists, mountain climbers, etc. The present system is more compact and provides easier movement for the wearer. In addition, the present invention can be designed to perform multiple functions. For example, the air conditioned jacket with multiple battery packs may also be used as a bullet proof jacket.